This invention is related to cutting tools such as taps, cut-off tools, grooving tools, drills, reamers, and the like, and more particularly to a method for forming a cutting tool by coating the entire surface of a high speed steel tool blank with a high hardness coating, heat treating to a required hardness, and then removing selected portions of both the blank and the coating such that the remaining coated blank forms a cutting edge.
Certain types of cutting tools are coated in a vapor chamber with a high hardness coating such as titanium nitride to provide a useful cutting life several times that of an uncoated tool. However, heat treating the tool after the coating is applied exposes the tool to a temperature which warps the tool so that it cannot meet precise tolerances. The tool is then useless for precision work.